Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Head-to-head comparison of ACP-105 and GSK-2881078 — mechanism, dosing, side effects, legal status, and pricing.
ACP-105 is a non-peptide nonsteroidal selective androgen receptor modulator (SARM) of the azabicyclooctane chemotype, structurally related to AC-262536 and RAD140. It acts as a partial agonist at the androgen receptor with tissue-selective anabolic effects demonstrated in preclinical models. ACP-105 is not an approved drug in any jurisdiction and has never entered human clinical trials. SARMs as a class are prohibited at all times under WADA Prohibited List S1.2 'Other Anabolic Agents'; ACP-105 falls under this class-wide ban and has been the subject of equine anti-doping metabolite-detection research.
GSK-2881078 is a nonsteroidal selective androgen receptor modulator (SARM) of the indole-5-carbonitrile chemotype, developed by GlaxoSmithKline to produce tissue-selective anabolic effects in skeletal muscle with reduced activity in androgen-sensitive tissues. It has been studied in three human clinical trials (Phase I and Phase IIa) but has never been approved for any indication and is not in active further development. SARMs as a pharmacological class are prohibited in sport at all times under WADA category S1.2 (Other Anabolic Agents), though GSK-2881078 is not individually named in reviewed WADA documents.
ACP-105
GSK-2881078
Category
Legal Status
Mechanism
Dose Range
Route
COA-verified vendors · trust score ≥70 required · single-vial price — bulk/bundle deals may be lower
ACP-105
GSK-2881078
COA corpus from Disclosed Labs — independently tested batches only.
ACP-105
2
COAs
99.3%
Avg purity
1
Labs
GSK-2881078
2
COAs
99.6%
Avg purity
2
Labs
No human data exist for ACP-105. In castrated male rats, 2-week oral dosing improved anabolic parameters consistent with tissue-selective partial AR agonism, suppressed the LH surge, and produced levator ani muscle anabolic effects. In female mice (whole-body irradiated and sham-irradiated), ACP-105 preserved rotorod sensorimotor performance impaired by radiation and enhanced cued fear conditioning while reducing MAP-2 immunoreactivity in sensorimotor cortex. In male gonadectomized 3xTg-AD Alzheimer's-model mice, ACP-105 alone reduced anxiety-like behavior; combined with the ER-beta agonist AC-186, it improved cognition (Morris water maze), increased amyloid-beta-degrading enzymes (neprilysin, IDE), and decreased brain amyloid-beta versus vehicle. Equine in vitro liver microsome studies identified twelve Phase I metabolites for doping-control detection purposes.
Key references
Human data are the most extensive of any compound in the SARM class: a Phase I first-in-human study in healthy men and postmenopausal women (Clark 2017) established dose-proportional systemic exposure and a long half-life (>100 hours) supporting once-daily dosing; a Phase I dose-escalation study in adults ≥50 years (Neil 2018) showed dose-dependent lean body mass gains (~3.39 kg in women, ~1.76 kg in men versus placebo at 8 weeks) accompanied by transient ALT elevations and 30–45% HDL-cholesterol reductions at the highest doses, both reversible on stopping treatment; and a Phase IIa randomized controlled trial in 97 COPD patients with muscle weakness (Mohan 2023) demonstrated increased lean body mass and leg-press strength (more consistently in men) over 13 weeks, with reversible HDL-C reduction and transient ALT increases as the main treatment-related safety signals. No peer-reviewed animal or in-vitro pharmacology/toxicology data for GSK-2881078 were located via PubMed or PubChem.
ACP-105 and GSK-2881078 are both in the Performance category and may have overlapping mechanisms. Researchers should review both profiles carefully, understand the mechanisms of action, and monitor the relevant biomarkers when combining compounds in the same class. As always, consult a licensed healthcare provider before making any decisions about combining research compounds.
This platform provides informational tools only, not medical advice. This comparison is for educational purposes only. Consult a licensed provider.
Frequency
Dosing Notes
Side Effects
Contraindications
Lab Testing
Key references
Disclosed Labs